An analytical framework for the study of rough-wall turbulent boundary layer

To study the dynamics of rough-wall turbulent boundary layer, an alternate set of transport equations that contain an implicit roughness drag and roughness production have been developed. The Canonical Reynolds averaged Navier-Stokes equations and transport equations are not well suited for this purpose, as they do not contain any roughness information. In this talk we present an analytical framework suitable for a rough-wall based on three-level decomposition of velocity. Direct numerical simulations have been used to simulate flow in a channel with rough-walls. We present the results for the transport equation of the mean momentum equation and discuss the significance of explicit roughness drag term that arises due to this formulation.